The present invention relates to an adjustable cutting insert cartridge for use in a boring bar. More particularly, the present invention relates to improvements in adjustable cartridge designs which increase the ease with which these cartridges can be manufactured and used.
Adjustable insert cartridges are designed to achieve the accurate and rapid adjustment of a cutting insert on a boring bar. These cartridges typically consist of a toolholder having a cutting insert on one end and a threaded shank on the other. The threaded shank is threadedly engaged in an adjusting nut or sleeve which is rotatably mounted in a collar which is bolted onto the boring bar. The threaded shank, sleeve and collar are fitted together in a manner that attempts to minimize play between them. This is usually accomplished through the use of a spring-like member that forces the components together. Examples of adjustable cartridge designs can be found in U.S. Pat. Nos. 3,313,187 and 3,434,376, both assigned to applicant corporation. While these designs have proven to be satisfactory in use, most of these designs do not allow for adjustment in the tension or load imparted to the various components in the cartridge by the spring. This means that the tolerances on the various components must be relatively tight to assure that the correct amount of loading is applied to the components.
This problem may be compounded by wear that occurs between the components during use. In one design which did allow for the adjustment of the load applied to the components (see U.S. Pat. No. 3,434,376, FIG. 5), the load adjusting components, while being held nonrotational with respect to the adjusting nut or sleeve, were mounted directly on the threaded shank of the toolholder.
In this design, in order to adjust the load by the relative rotation of one of the load adjusting members relative to the adjusting nut or sleeve, first the load adjusting members had to be partially disassembled, the member rotated to the desired position, and then reassembled. This is both inconvenient and time consuming.